Expansion joint for concrete works

ABSTRACT

An expansion joint for concrete works, especially for paving concrete-based surfaces, in which said joint initially acts as a screed bar and guide rail for classic surface vibrators, which is formed by means of the functional combination of two profiled metallic pieces ( 1, 2 ), having a considerable length, essentially having a right triangular section, coupled by means of tongue and groove through one of their lateral sides ( 3 ), corresponding to one of the catheti of their section, such that both pieces together configure an isosceles triangle profile resting on the ground by means of height-adjustable supports and incorporating in correspondence with their top edge a pair of plastic strips ( 9 ) forming said guide for the surface vibrators.

OBJECT OF THE INVENTION

The present invention refers to an expansion joint particularly designed for concrete works, specifically for obtaining concrete paving in which once the concrete is poured on site, it is necessary to extend it in order to achieve pavement with a smooth surface and at the required height.

The joint of the invention is not only usable as an expansion joint but also as a screed bar, as a guide rail for the concrete surface vibrators, as an enclosure panel, as a working joint and as a contraction joint.

The object of the invention is to prevent cracks due to straining, to prevent hydraulic and thermal retraction, to absorb the stresses from the concrete, to protect the edges thereof, to prevent the leveling difference of the working joint due to buckling, to prevent the joint from projecting from the concrete level during the curing process, and to increase the possibility of achieving a more planar floor.

BACKGROUND OF THE INVENTION

Several methods are currently used to pave a surface with concrete as the raw material, among which the following can be mentioned:

-   -   The use of fixed bars (screeds) on the entire surface, making         passages of about 6 meters wide, which bars are placed at the         level of the working height and act as guides and supports for         the surface vibrating screed. This method assures good         horizontal alignment when carried out, as long as special         single-use bars are used. When using this system it is necessary         to arrange working joints and, on large outside surfaces,         expansion joints.     -   The laser method, not as effective as the previous one, takes         the reference height while in motion and, while the concrete is         being poured, the laser receiver and the leveling rod or staff         supporting said receiver is placed above the unsettled concrete,         taking reference points (screeds), the stability of which leaves         much to be desired since the same people spreading the concrete         next to the screeds may easily modify the reference height.         Occasionally the leveling rod supporting the receiver is not         completely perpendicular to the ground, which also modifies the         laser reading with respect to the level of the real working         height. All these factors cause detecting an uneven surface full         of bumps and with several centimeters of difference with respect         to the actual reference height once the concrete flooring is         finished and analyzed. When using the laser method it is         necessary to arrange working joints, to cut a contraction joint         and, on large or outside surfaces, to also arrange expansion         joints.     -   The third method consists of the use of automatic leveling         machines which, although they offer better results than those of         the laser method, they do not allow obtaining works with a high         horizontal alignment since the hydraulic system as of today         cannot assure millimetric precision, without taking into account         that the system is assembled on floating extendable arms that         are manually collected by an operator and that any abrupt         movement may cause a reciprocating movement in the arms         supporting the vibrating screed, transmitting these vibrations         to the pavement. In this case it is also necessary to use         working joints, to make a contraction cut and, on large or         outside surfaces, to arrange expansion joints.

DESCRIPTION OF THE INVENTION

The expansion joint proposed by the invention is especially suitable for being applied to the first one of the previously mentioned methods since, in theory, it constitutes a screed bar which further acts, as previously stated, as a guide rail for surface vibrators, which can be used as an enclosure panel or as a working joint and which can further make up a contraction and expansion joint.

To that end and more specifically, the joint proposed by the invention is formed by means of the functional combination of two pieces basically profiled according to a rectangular triangle, having a suitable length, such as 3 meters for example, with the special particularity that said pieces are coupled by tongue and groove through one of their sides, specifically through their coupling sides corresponding to one of the catheti of its section, one of said pieces having a rectangular grooving while the other one has a complementary outward or male deformation, such that the combination of both pieces in turn generates a new profile, in this case having a basically isosceles triangular section.

According to another feature of the invention each of the mentioned pieces incorporates a plastic strip corresponding with its upper edge or vertex, such that in the assembly of both pieces the respective plastic strips make contact with one another and slightly project with respect to the double metallic profile.

Both the top lateral side corresponding to the hypotenuse of their section and the bottom face of the two pieces of the joint have many openings for allowing the concrete to enter inside them, which does not occur with their sides that couple together, which are completely closed.

Finally and according to another feature of the invention, the two metal pieces forming the joint are in turn provided with special openings at suitably spaced and sized intervals for the coupling of vertical pins intended for being nailed in the ground and supporting the joint, with the ability to adjust the height for the joint, for which purpose a transverse stud bolt, also arranged on the corresponding piece, collaborates with each vertical pin.

DESCRIPTION OF THE DRAWINGS

To complement the description being made and for the purpose of aiding to better understand the features of the invention, according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description in which the following is shown with an illustrative and non-limiting character:

FIG. 1 shows a partial perspective view of an expansion joint for concrete works carried out according to the object of the present invention, which is shown without its support pins on the ground.

FIG. 2 shows a schematic profile representation of the joint of the previous figure, now supported on the ground but with its two pieces uncoupled to show its structure with greater clarity.

FIG. 3 shows a perspective view of a detail of one of the pieces forming the joint at the level of one of the support pins thereof.

Finally, FIG. 4 shows a sectional view of a detail similar to the profile of FIG. 2, but with the two pieces of the joint duly coupled together and with said joint immersed in the concrete mass forming the pavement.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the discussed figures, it can be seen how the expansion joint proposed by the invention is structured by means of two tubular and metallic profiled pieces (1) and (2), basically having a right triangular section, one of them (1) provided on its side (3) that couples to the other one with a wide rectangular grooving (4), while the other one (2) has an also rectangular outward deformation (5) intended for fitting into the grooving (4) in order to form a tongue and groove coupling, as can be observed in either one of FIGS. 2 and 4, such that after the coupling between these pieces (1) and (2), the joint as a whole adopts an isosceles triangle profile, for example with a length of 3 meters, a height comprised between 10 and 15 cm, and a width in the order of 12 cm, dimensions mentioned merely as an example, for obtaining a pavement with a standard thickness.

The pieces (1) and (2) are provided on their top lateral sides and on their bottom sides with many openings (6) allowing the free passage of the concrete (7) towards the inside and through the joint itself, the inner walls (3) joined between pieces (1) and (2) lacking openings however.

A small longitudinal grooving (8), particularly visible in the enlarged detail of FIG. 2, is defined at the top level in each one of these pieces (1) and (2) in correspondence with their also top edge, intended for the coupling of a plastic strip (9) which, together with that of the other part, finishes the joint on the top portion forming the top edge thereof.

Finally, each one of the pieces (1) and (2) incorporates in points suitably spaced along the length thereof, special openings (10) for the passage of respective vertical pins (11) which, intended for being supported on the ground (12), as can be especially observed in FIG. 4, allow adjusting the height of the triangular profile formed by the pieces (1) and (2) and suitably fixing any position chosen for them, with the collaboration of side stud bolts (13) which in turn act in openings (14) of pieces (1) and (2) as nuts.

These pins (11), having a considerable length, allow an also considerable adjustment of the height for the profile formed by the pieces (1-2), which in turn allows using the latter as a light, self-supporting, fast and easy leveling screed bar that does not require subsequent stripping.

Due to their own plastic nature and their reduced surface, the plastic strips (9) arranged on the top edge or border of said bar very considerably facilitate movement of the surface vibrator while at the same time they are capable of supporting it without undergoing deformations.

The double profile can also be used as an enclosure panel, that is, as a formwork periphery limiting element, also being light, easy to release, self-supporting and simultaneously acting as a contraction joint, working joint and expansion joint.

Specifically from the point of view of a working joint, it prevents the vertical movement due to buckling and retraction, due to the tongue and groove fitting between the two pieces forming the joint, and on the other hand the plastic strips (9) wear as the concrete descends 2 mm in its curing process, the bar always being at the same level as the concrete and said plastic strips at all times acting as protection means for the sharp corners of the concrete, features that are also maintained when the profile works as a contraction joint and as an expansion joint.

It must finally be mentioned that in certain cases, one of the two pieces (1-2) forming the joint may be used separately. 

1. An expansion joint for concrete works, especially for paving concrete-based surfaces, in which said joint initially acts as a screed bar and guide rail for classic surface vibrators, wherein it is formed by means of the functional combination of two profiled metallic pieces (1, 2), having a considerable length, essentially having a right triangular section, that are coupled by means of tongue and groove through one of their lateral sides (3), corresponding to one of the catheti of their section, such that both pieces together configure an isosceles triangle profile resting on the ground through height-adjustable supports and incorporating in correspondence with their top edge a pair of plastic strips (9) forming said guide for the surface vibrators.
 2. An expansion joint for concrete works according to claim 1, wherein one of said pieces incorporates a wide side grooving (4) having a rectangular section for its tongue and groove coupling to the other piece, while the second piece incorporates a complementary outward deformation (5), also having a rectangular section, that is tightly coupled into said grooving.
 3. An expansion joint for concrete works according to claim 1, wherein each of the two metallic pieces incorporates in correspondence with its top vertex a small longitudinal grooving (8) open at the top portion, for coupling of the correspond plastic strip (9) substantially projecting from said grooving.
 4. An expansion joint for concrete works according to claim 1, wherein the top lateral side and bottom side of each profiled metallic piece incorporates a plurality of wide openings (6) allowing the passage therethrough of the concrete forming the pavement, whereas the inner walls through which both pieces are coupled together are closed.
 5. An expansion joint for concrete works according to claim 1, wherein each of the two profiled metallic pieces forming the joint is provided, at suitably spaced and distributed points, with vertically aligned openings (10) for the passage of respective vertical pins (11) acting as support and leveling means for the joint with which respective side stud bolts (13) collaborate, fixing the profiled pieces to said pins at any chosen height.
 6. An expansion joint for concrete works according to claim 5, wherein in addition to acting as such an expansion joint, it acts as a screed bar, a guide rail for the surface vibrators, an enclosure panel, a working joint and a contraction joint. 